BACKGROUND
I. Field
[0001] The following description relates generally to wireless communications, and more
particularly to open loop power control in a wireless communication environment.
II. Background
[0002] Wireless communication systems are widely deployed to provide various types of communication
and have become a prevalent means by which a large number of people worldwide communicate.
A typical wireless communication system or network can provide multiple users access
to one or more shared resources. For instance, a system may use a variety of multiple
access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing
(TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing
(OFDM), and others. Wireless communication devices have become smaller and more powerful
to meet consumer needs, which include improved portability and convenience. Users
have found many uses for wireless communication devices, such as cellular telephones,
personal digital assistants (PDAs), and the like, and such users demand reliable service
and expanded coverage areas.
[0003] Wireless communications networks are commonly utilized to communicate information
regardless of where a user is located (inside or outside a structure) and whether
a user is stationary or moving (e.g. in a vehicle, walking). Generally, wireless communications
networks are established through a mobile device communicating with a base station
or access point. The access point covers a geographic region or cell and, as the mobile
device is operated, the mobile device may move in and out of these geographic cells.
To achieve uninterrupted communication, the mobile device is assigned resources of
a cell it has entered and de-assigned resources of a cell it has exited.
[0004] To effectuate continued coverage, access points associated with networks are geographically
positioned so as users change location they do not lose services. Thus, mobile devices
can be "handed off" from a first base station to a second base station. In other words,
a mobile station will be serviced by a first base station while in a geographic region
associated with such base station. When the mobile device is transported to a region
associated with a second base station, the mobile device will be handed off from the
first base station to the second base station. Ideally, the handoff occurs without
data loss, loss of service, and the like. However, if it takes a mobile device an
excessive amount of time to establish communication with a base station, the call
might be lost or communications interrupted. In addition, inadequate communication
with a base station might cause interference to neighboring devices.
SUMMARY
[0005] The following presents a simplified summary of one or more aspects in order to provide
a basic understanding of such aspects. This summary is not an extensive overview of
all contemplated aspects, and is intended to neither identify key or critical elements
of all aspects nor delineate the scope of any or all aspects. Its sole purpose is
to present some concepts of one or more aspects in a simplified form as a prelude
to the more detailed description that is presented later.
[0006] In accordance with one or more examples and corresponding disclosure thereof, various
aspects are described in connection with facilitating automatic correction of broadcast
information through a feedback mechanism so that subsequent broadcast communications
include information that is more accurate. Information included in a broadcast signal
can relate to information necessary for a device to communicate with base stations
or other devices in a vicinity of the device. As such, broadcast information can include
an access point transmit power, an access point receive power target, power loss,
and other information. If the broadcast information is determined to be incorrect,
the access point (or other device that broadcast the information) can receive a recommended
modification and selectively apply such modification to information contained in a
subsequent broadcast signal.
[0007] Another aspect relates to a method that facilitates selective adjustment of power
control information sent in a broadcast signal. The method can include receiving,
from an access point, a broadcast signal that includes power control information and
ascertaining if a correction is recommended for the broadcast power control information.
The recommended correction can be conveyed to the access point.
[0008] Another aspect relates to a wireless communications apparatus that includes a memory
and a processor. The memory can retain instructions related to evaluating power control
information included in a broadcast signal, determining if there is at least one error
in the information and notifying an access point of the at least one error in a feedback
signal. The processor can be coupled to the memory and configured to execute the instructions
retained in the memory.
[0009] Yet another aspect relates to a wireless communications apparatus that enables selective
modification of broadcast information within a wireless communications environment.
The apparatus can include a means for identifying incorrect information included in
a signal from an access point and a means for determining a recommended modification
for the identified incorrect information. Also included in apparatus can be a means
for sending the recommended modification in a feedback signal to the access point.
[0010] Still another aspect relates to a machine-readable medium having stored thereon machine-executable
instructions for evaluating a correctness of a signal from an access point; and determining
at least one recommended change to the signal. The instructions can also include sending
the at least one recommended change to the access point in a feedback signal.
[0011] A further aspect relates to an apparatus that includes a processor, the apparatus
is in a wireless communication system. The processor can be configured to identify
inaccurate information included in a signal from an access point. Additionally processor
can be configured to determine a change that will correct the inaccurate information
and provide to the access point a feedback signal that includes the determined change.
The determined change can be based at least in part on information included in the
signal.
[0012] Still another aspect relates to a method that facilitates selective adjustment of
information included in a broadcast signal. The method can include broadcasting a
signal that includes power control information. The signal can be broadcast to at
least one device within a geographic area. The method can further include receiving
from the at least one device a reply signal that includes at least one modification
to the power control information included in the broadcast signal and selectively
applying the at least one modification to the power control information included in
the broadcast signal.
[0013] Yet another aspect relates to a wireless communications apparatus that includes a
memory and a processor. The memory can retain instructions related to determining
information to include in a broadcast signal; receiving a device recommendation to
update information included in the broadcast signal, and selectively modifying the
broadcast signal information based in part on the received device recommendation.
The processor can be coupled to the memory and configured to execute the instructions
retained in the memory.
[0014] Another aspect relates to a wireless communications apparatus that mitigates a length
of an initial access phase in a wireless environment. The apparatus can include a
means for identifying information to include in a broadcast signal sent to a plurality
of devices and a means for receiving at least one reply signal from at least one of
the plurality of devices in response to the broadcast signal. Also included in the
apparatus can be a means for changing at least a subset of the information included
in the broadcast signal based in part on the at least one reply signal.
[0015] Still another aspect can relate to a machine-readable medium having stored thereon
machine-executable instructions for transmitting a signal that at least one device
relies upon to gain access to a communications network and evaluating feedback from
the at least one device to identify incorrect information included in the transmitted
signal. The instructions also relate to adapting the transmitted signal based upon
the feedback evaluation.
[0016] Yet another aspect relates to an apparatus in a wireless communication system. The
apparatus can include a processor that can be configured to identify information to
include in a broadcast signal that is sent to a plurality of devices. The process
can further be configured to evaluate one or more modifications to the information
in the broadcast signal, the one or more modifications are received from a subset
of the plurality of devices and modify the information included in a subsequent broadcast
signal based on the one or more modifications received.
[0017] To the accomplishment of the foregoing and related ends, the one or more examples
comprise the features hereinafter fully described and particularly pointed out in
the claims. The following description and the annexed drawings set forth in detail
certain illustrative aspects of the one or more examples. These aspects are indicative,
however, of but a few of the various ways in which the principles of various examples
may be employed and the described examples are intended to include all such aspects
and their equivalents.
[0018] To the accomplishment of the foregoing and related ends, the one or more examples
comprise the features hereinafter fully described and particularly pointed out in
the claims. The following description and the annexed drawings set forth in detail
certain illustrative aspects of the one or more examples. These aspects are indicative,
however, of but a few of the various ways in which the principles of various examples
may be employed and the described examples are intended to include all such aspects
and their equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a wireless communication system in accordance with various aspects
set forth herein.
[0020] FIG. 2 illustrates an example system that selectively updates broadcast information
in a wireless communication environment.
[0021] FIG. 3 illustrates an example system that enables correction of broadcast information
for subsequent transmissions in a wireless communication environment.
[0022] FIG. 4 illustrates an example communications network that facilitates automatic correction
of broadcast information through a feedback mechanism.
[0023] FIG. 5 illustrates an example methodology that facilitates broadcasting corrected
information within a wireless communication environment.
[0024] FIG. 6 illustrates an example methodology that facilitates selectively adjusting
and reporting information modifications within a wireless communication environment.
[0025] FIG. 7 illustrates an example communication system implemented in accordance with
various aspects including multiple cells.
[0026] FIG. 8 illustrates an example base station in accordance with various aspects.
[0027] FIG. 9 illustrates an example wireless terminal (e.g., mobile device, end node, and
so forth) implemented in accordance with various aspects described herein.
[0028] FIG. 10 illustrates an example system that enables selective modification of broadcast
information within a wireless communications environment.
[0029] FIG. 11 illustrates an example system that can mitigate a length of an initial access
phase in a wireless environment.
DETAILED DESCRIPTION
[0030] Various examples are now described with reference to the drawings, wherein like reference
numerals are used to refer to like elements throughout. In the following description,
for purposes of explanation, numerous specific details are set forth in order to provide
a thorough understanding of one or more examples. It may be evident, however, that
such examples may be practiced without these specific details. In other instances,
well-known structures and devices are shown in block diagram form in order to facilitate
describing one or more examples.
[0031] As used in this application, the terms "component," "module," "system," and the like
are intended to refer to a computer-related entity, either hardware, firmware, a combination
of hardware and software, software, or software in execution. For example, a component
may be, but is not limited to being, a process running on a processor, a processor,
an object, an executable, a thread of execution, a program, and/or a computer. By
way of illustration, both an application running on a computing device and the computing
device can be a component. One or more components can reside within a process and/or
thread of execution and a component may be localized on one computer and/or distributed
between two or more computers. In addition, these components can execute from various
computer readable media having various data structures stored thereon. The components
may communicate by way of local and/or remote processes such as in accordance with
a signal having one or more data packets (e.g., data from one component interacting
with another component in a local system, distributed system, and/or across a network
such as the Internet with other systems by way of the signal).
[0032] Furthermore, various aspects are described herein in connection with a wireless terminal.
A wireless terminal can also be called a system, subscriber unit, subscriber station,
mobile station, mobile, mobile device, remote station, remote terminal, access terminal,
user terminal, terminal, wireless communication device, user agent, user device, or
user equipment (UE). A wireless terminal may be a cellular phone, a cordless telephone,
a smart phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL)
station, a personal digital assistant (PDA), a laptop, a handheld communication device,
a handheld computing device, a computing device, a satellite radio, a global positioning
system, a processing device connected to a wireless modem and/or other suitable devices
for communication. Moreover, various aspects are described herein in connection with
a base station. A base station may be utilized for communicating with wireless terminal(s)
and may also be referred to as an access point, Node B, or some other terminology.
[0033] Moreover, various aspects or features described herein may be implemented as a method,
apparatus, or article of manufacture using standard programming and/or engineering
techniques. The term "article of manufacture" as used herein is intended to encompass
a computer program accessible from any computer-readable device, carrier, or media.
For example, computer-readable media can include but are not limited to magnetic storage
devices (e.g., hard disk, floppy disk, magnetic strips, an so forth), optical disks
(e.g., compact disk (CD), digital versatile disk (DVD), and the like), smart cards,
and flash memory devices (e.g., EPROM, card, stick, key drive, and so on). Additionally,
various storage media described herein can represent one or more devices and/or other
machine-readable media for storing information. The term "machine-readable medium"
can include, without being limited to, wireless channels and various other media capable
of storing, containing, and/or carrying instruction(s) and/or data.
[0034] Referring now to Fig. 1, illustrated is a wireless communication system or multi-user
wireless environment 100 in accordance with the various aspects disclosed herein.
System 100 can comprise one or more base stations 102 (e.g., access points) in on
or more sectors that receive, transmit, repeat, etc., wireless communication signals
to each other and/or to one or more mobile devices 104. Each base station 102 can
comprise a transmitter chain and a receiver chain, each of which can in turn comprise
a plurality of components associated with signal transmission and reception (
e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, and
so one) as will be appreciated by one skilled in the art. Base stations 102 can transmit
information to mobile devices 104 over forward links (downlinks) and receive information
from mobile devices 104 over reverse links (uplinks). Base station 102 can transmit
broadcast signals that include information that allow mobile devices 104 to identify
and communicate with base station 102. The broadcast signal can include various information
including access point pilot tones and/or power level information.
[0035] In a multi-user wireless network, as illustrated by system 100, mobile devices 104
should limit their transmit powers to a nominal level in order to mitigate an amount
of interference caused to other mobile devices 104. Transmitting using very little
power, however, places the mobile device 104 at a risk of not being heard by the base
station 102. Thus, excessive transmit power can lead to undesired interference to
other mobile devices that share the medium, while too little power can cause a communication
failure. An approach that can be utilized to provide mitigation of interference is
through a closed-loop power control where base station 102 monitors a received power
from individual mobile devices 104 and informs mobile devices 104 to adjust their
transmit powers to a desired level. For the closed-loop power control to operate properly,
mobile device 104 should be transmitting a signal. Thus, this approach might not be
utilized during the initial access phase where mobile device 104 has not yet started
transmitting.
[0036] A procedure for controlling a mobile device power in the initial access phase can
be through an open loop power control where mobile device 104 estimates its target
transmit power based on a power of a received signal. This can assume substantially
the same forward link and reverse link losses and that the difference between the
mobile device transmit power and receive power is a constant offset. This offset can
be referred to as the Open Loop Power Offset (OLPO). An estimate of the OLPO can be
computed by mobile device 104 or it can be computed by base station 102 and communicated
to mobile device 104. Mobile device 104 can add the OLPO estimate value to the measured
received power to obtain an initial transmit power (
e.g., final offset value).
[0037] Due to several unknowns and variations in the system 100, the estimate may be inaccurate.
This can cause the mobile device transmit power to either overshoot (e.g. causing
excessive interference) or fall short of the desired level (
e.g., failed access connection and so forth). In either situation, mobile device 104 would
blindly increase and/or decrease its power gradually until an acknowledgement of a
successful mobile device 104 transmission is received from base station 102. This
extra step of power search can prolong an initial access phase, resulting in a lost
communication signal or other problems.
[0038] In accordance with the disclosed aspects, the extra step can be mitigated for subsequent
mobile devices 104 that initiate communication with base station 102. For example,
upon successful access, a mobile device 104 can report its measured final offset value
to base station 102. Base station 102 can update its estimate of the OLPO based on
reports from one or more mobile devices 104 and base station 102 can use this new
value for future attempts (e.g., subsequent broadcast signals), which can mitigate
excessive access times for subsequent access attempts by other mobile devices 104.
Thus, the various aspects can provide quicker and potentially more accurate open loop
power control between base station 102 and mobile devices 104 by updating the power
offset values, if needed. These changes can be made when a mobile device 104 successfully
achieves access to the base station 102 or when base station 102 achieves an adequate
confidence level relating to the accuracy of the recommendation to change the broadcast
information (e.g., confirmation from more than one device, average of all changes
received in a given interval or other criteria and so forth).
[0039] Fig. 2 is an illustration of an example system 200 that enables correction of broadcast
information for subsequent transmissions in a wireless communication environment.
Included in system 200 are an access point 202 and a mobile device 204. It should
be understood that system 200 can include more access points and mobile devices and
one of each is illustrated and described for simplicity purposes. Access point 202
can broadcast information that allows mobile device 204 to identify and establish
communication with access point 202. Included in a broadcast signal should be at least
an access point transmit power and an access point receive power target.
[0040] An example of incorrect information that can be corrected with the disclosed features
is offset information, although other information and calculations can also be corrected.
As it relates to offset information, at substantially the same time as mobile device
204 is in communication with access point 202, mobile device 204 can measure a power
offset and determine what power offset information should have been included in the
information broadcast by access point 202 to allow mobile devices to more readily
establish communication with access point 202. Mobile device 204 can communicate this
corrected information to access point 202 utilizing a feedback or reply signal.
[0041] If further detail, mobile device 204 can include a receiver 206 that can be configured
to receive information included the broadcast signal from base station 202 (as well
as other communication signals from base station 202 and other devices). Once a connection
is established between mobile device 204 and access point 202, access point 202 can
monitor an incoming mobile device power and send corrections to mobile device 204.
Such corrections can instruct mobile device 204 to adjust its power so that signals
arrive at access point 202 at a desired Signal to Noise Ratio (SNR). The SNR is a
measurement of the relative level of noise within a network and can correspond to
a transmission quality. SNR is the ratio of the usable signal being transmitted to
the noise or undesired signal.
[0042] An access request is generally the first signal that mobile device 204 transmits
to access point 202, through a transmitter 208, for example. Thus, prior to receiving
this signal, access point 202 is not aware of the power level at which signals from
mobile device 204 will arrive. However, based on an access point transmit power (AP
TxPwr) information included in the broadcast signal, a power offset evaluator 210 associated
with mobile device 204, can ascertain a rough adjustment of the transmit power at
which is should transmit (AT
TxPwr), utilizing a closed-loop power control. The mobile device transmit power (AT
TxPwr) can be based on a power (AT
RxPwr) at which mobile device 204 receives the signal plus any path losses (L). Thus,

and solving for the path losses (L):

[0043] Based on the determined path losses (L), transmit power assigner 212, can set the
mobile device transmit power (AT
TxPwr) to the determined path losses (L) plus the access point receive power target (AP
RxPwr):

thus,

[0044] The process described above is commonly referred to as open loop power control and
has several deficiencies that can be overcome with the aspects disclosed herein. For
example, there can be some calibration error and/or errors in measuring the received
pilot power and/or the device transmit power. The result of such errors might result
in the initial access from mobile device 204 coming in at too high a power or at too
low a power. If the power is too high, it can cause interference to the other mobile
devices 204 within system 200. If the power is too low, access point 202 might not
hear the communication from mobile device 204, which can result in a delay before
mobile device 204 can communicate with access point 202. The transmit power of mobile
device 204 can be altered until mobile device 204 eventually can communicate with
access point 202, resulting in delay while the power is altered. This slight delay
can cause problems especially during handoff when it is important to establish a connection
quickly. The disclosed aspects can mitigate the delay for subsequent mobile devices
to achieve communication with access point 202.
[0045] The access point receive power target (AP
RxPwr) or offset value information can be communicated to access point by information notifier
214. The communication can include a recommendation to adjust information in the broadcast
signal so that the signal includes correct information relating to the offset value
so that devices that receive the broadcast signal are aware and can quickly calculate
the value at which mobile devices should transmit. It should be understood that other
corrections to the broadcast signal information can be applied utilized the disclosed
features.
[0046] Access point 202 can modify the broadcast information based on the recommendation
(e.g., rely on the received recommendation). Access point 202 can solicit and receive
confirmation from one or more mobile devices before changing the information. Alternatively
or additionally, access point 202 can wait until a predetermined number of similar
recommendations are received and adjust the broadcast information based on an average
or other compilation of all the received recommendations. Access point 202 may establish
other criteria (e.g., confidence level) in order to establish verification before
changing information included in a broadcast signal.
[0047] A memory 216 can be operatively coupled to mobile device 204. Memory 216 can store
information related to mobile device identification information, mobile device transmit
power, path losses, access point receive power target, access point transmit power,
OLPO and other suitable information related to verifying information included in a
signal received from access point 202. Memory 216 can retain instructions related
to evaluating information included in a broadcast signal, determining if there is
at least one error in the information and notifying access point 202 of the at least
one error in a feedback signal. A recommendation can be sent to access point 202 to
correct the error in a next broadcast signal. The error can relate to a power offset
value and/or other information included in the broadcast signal. Additionally and/or
alternatively memory 216 can retain instructions for notifying access point 202 if
the information contained in the broadcast signal is correct. Additionally, memory
216 can retain instructions for determining a power offset value by comparing an access
point transmit power with a device receive power and setting a transmit power of mobile
device 204 to a sum of the offset value and an access point receive power target.
In accordance with some aspects, memory 216 can retain instructions for reviewing
a next broadcast signal and providing information relating to an accuracy of the next
broadcast signal.
[0048] Memory 216 can store protocols associated with generating acknowledgments, recommending
changes to broadcast information, taking action to control communication between mobile
device 204 and access point 202,
etc., such that system 200 can employ stored protocols and/or algorithms to achieve improved
communications in a wireless network as described herein. It should be appreciated
that the data store (e.g., memories) components described herein can be either volatile
memory or nonvolatile memory, or can include both volatile and nonvolatile memory.
By way of example and not limitation, nonvolatile memory can include read only memory
(ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically
erasable ROM (EEPROM), or flash memory. Volatile memory can include random access
memory (RAM), which acts as external cache memory. By way of example and not limitation,
RAM is available in many forms such as synchronous RAM (DRAM), dynamic RAM (DRAM),
synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM),
Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM). Memory 216 of the disclosed
aspects are intend to comprise, without being limited to, these and other suitable
types of memory.
[0049] A processor 218 can be operatively connected to mobile device 204 (and/or memory
216) and can be configured to execute the instructions retained in the memory. Process
218 can also be configured to facilitate analysis of information related to correcting
information in system 200. Processor 218 can be a processor dedicated to analyzing
and/or generating information received by receiver 206, a processor that controls
one or more components of system 200, and/or a processor that both analyzes and generates
information and controls one or more components of system 200.
[0050] Now referring to Fig. 3, illustrated is an example system 300 that selectively updates
broadcast information in a wireless communication environment. System 300 includes
at least one access point 302 and at least one mobile device 304. Access point 302
includes a transmitter 306 that can continuously or periodically broadcast forward
link information that allows mobile devices 304 within a geographic range of access
point 302 to identify access point 302 (or network) and selectively gain access to
access point 302. Such selective access can be based on various criteria including
strength of the signal or quality of the signal, as well as other factors. According
to an example, the broadcast information can include an access point transmit power,
an access point receive power target, an amount of power loss, power offset information,
a corrected delta value, or combinations thereof and/or other information.
[0051] Mobile device 304 can measure a pilot power from information included in the broadcast
signal. The pilot power is the transmit power of the access point minus any path losses.
Path losses are defined as the power loss that occurs when radio waves move through
space during specific paths. Mobile device 304 can solve for the path loss power (L)
by subtracting a received pilot power (Pow
RxPil) from the access point transmit power:

where
PowTxPil is the total pilot power of access point 302.
LDL symbolizes the downlink path loss. It should be noted that Equation 4 is substantially
the same as Equation 1. For the uplink access request to arrive at the desired SNR
level, the access point receive power
PowRxgcs should be:

or similarly on the mobile side:

assuming that
LDL is equal to
LUL, then:

[0052] Both terms,
PowTxPil and
PowRxAcs can be known by access point 302. Thus, access point 302 can communicate the right
hand side of Equation 8,
Z = PowRxAcs + PowTxPil to mobile device 304 through a broadcast channel. The parameter Z is referred to
as the open-loop gain offset. Mobile device 304 can add the Z offset to its received
pilot power to obtain an estimated figure for its initial transmit power.

If mobile device 304 is unsuccessful in gaining access, it may reattempt accessing
at different power levels, either higher or lower than the initial access power from
Equation 9. Eventually, if mobile device 304 gain access, mobile device 304 can report
to access point 302 the final open loop power gain offset
Zfinal at which mobile device 304 was able to connect to access point 302. Access point
302 can use
Zfinal to fine tune its copy of the gain offset and include such value in its broadcast
signal.
[0053] To facilitate selective updates to broadcast information, at substantially the same
time as mobile device 304 receives the broadcast information, it may notify access
point 302 of any incorrect data and/or offer a recommendation as to what will correct
the information. Mobile devices 304 can be configured to perform such notification
automatically or access point 302 may specifically request such information.
[0054] A broadcast information adjuster 310 can be configured to selectively modify or adapt
information in the broadcast signal for future broadcasts. For example, broadcast
information adjuster 310 can modify the broadcast information at substantially the
same time as a correction notification or recommendation is received from mobile device
304. Additionally or alternatively, broadcast information adjuster 310 might solicit
verification from other mobile devices to determine whether the corrected information
received from mobile device 304 is accurate. Depending on the recommended changes,
broadcast information adjuster 310 might not modify the information including in the
broadcast signal. Alternatively or additionally, if different information is received
from mobile devices 304, broadcast information adjuster 310 can average the changes
received, can take a median of recent reports or apply any other meaningful statistical
measure and send the change to the broadcast information. Other modifications, adjustments,
or acceptance of the received recommended changes can be implemented by broadcast
information adjuster 310.
[0055] A subsequent mobile device receiving the broadcast signal (e.g., new device entering
a geographic range of an access point) can benefit from more accurate information
(e.g., modified information) within the broadcast signal. As such, these subsequent
mobile devices can more efficiently establish and maintain communications with access
point 302. If there are additional modifications that should be made (
e.g., the information is still incorrect or other information is determined to be incorrect),
the subsequent mobile device can recommend such modifications in a similar manner
as described above. If the information is acceptable (e.g., correct), subsequent mobile
devices do not have to send information informing access point 302 that the information
is correct. However, this information can be communicated to access point 302 in accordance
with some aspects.
[0056] A memory 312 can be operatively coupled to access point 302. Memory 312 can store
information and/or retain instructions relating to determining information to include
in a broadcast signal. Such information in the broadcast signal can relate to at least
one of an access point transmit power, an access point receive power target, a path
loss, or a power offset, or combinations thereof. Memory 312 can further store information
and/or retain instructions relating to receiving a device recommendation to update
information included in the broadcast signal and selectively modifying the broadcast
signal information based in part on the received device recommendation. Additionally,
memory 312 can store information and/or retain instructions for determining a confidence
level associated with the device that provided the recommendation, for requesting
corroboration of the provided recommendation from at least a second device, for requesting
confirmation of the information included in the broadcast signal, for averaging values
received from a plurality of devices before selectively modifying the information
in the broadcast signal, for receiving feedback from the device that provided the
recommendation after modifying the broadcast signal to verify appropriate modifications
were made and/or other suitable information related to updating and verifying the
accuracy of information included in a broadcast signal.
[0057] A processor 314 can be operatively connected to access point 302 (and/or memory 312)
to facilitate analysis of information related to updating and verifying broadcast
information and/or can be configured to execute the instructions retained in memory
312. Processor 314 can be a processor dedicated to analyzing information received
by receiver 308 and/or generating information that can be utilized by transmitter
306 and/or broadcast information adjuster 310, a processor that controls one or more
components of system 300, and/or a processor that analyzes information, generates
information and controls one or more components of system 300.
[0058] With reference to
Fig. 4 is an illustration of an example communications network 400 that facilitates automatic
correction of broadcast information through a feedback mechanism. System 400 can be
configured to modify information determined to be incorrect and apply such modified
information selectively to subsequent communications. The information can be broadcast
to a multitude of devices within the vicinity wherein such devices partially or completely
rely on such broadcast information (e.g., power offset information).
[0059] In further detail, system includes an access point 402 and mobile devices 404 and
406. Mobile device 404 can be a first device that enters a geographic range of access
point 402 and second mobile device 406 can enter the geographic range of access point
402 after first mobile device 404. Access point 402 can periodically or continuously
transmit or broadcast forward link information, illustrated at 408 (and 414). Such
information allows devices 404, 406 within the vicinity to utilize access point 402
selectively. Such selective utilization can be based on various criteria including
strength of the signal or quality of the signal, as well as other factors. The broadcast
information can include an access point transmit power, an access point receive power
target and/or other information.
[0060] First mobile device 404 can measure a received pilot power, which is the access point's
transmit power minus any path losses. Mobile device 404 can solve for the path loss
power (L) by subtracting the received pilot power from the broadcast access point
transmit power. Mobile device 404 can set its transmit power to the access point receive
power plus the determined path loss. Mobile device 404 can send communications 410
to access point 402 utilizing the determined transmit power level.
[0061] The process described above is commonly referred to as open loop power control and
has several deficiencies that can be overcome with the disclosed features. A deficiency
is that there can be some calibration error and/or errors in measuring the received
pilot power and/or the device transmit power. The result of such errors might result
in the initial access coming in at too high of a power or too low of a power. If the
power is too high, it can cause interference. If the power is too low, the access
point might not hear the communication from mobile device. An error in calibration
and/or measurement will result in a delay before mobile device can communicate with
the access point. This delay is a function of mobile device altering its transmit
power until it eventually can communicate with the access point. This slight delay
can cause problems especially during handoff when it is important to establish the
connection quickly.
[0062] The disclosed aspects overcome this delay so that subsequent mobile devices 406 that
come within the range of access point 402 can obtain quick communication with access
point 402. Mobile device 404 receives the broadcast information in a forward link
408 from base station 402 and calculates its device transmit power similar to the
process described above. After mobile device 404 is in communication with access point
402, it measures the power offset and determines what power offset information should
have been broadcast by access point 402. Mobile device 404 communicates this offset
information to access point 402 in a feedback loop illustrated at 412.
[0063] Access point 402 can selectively modify its broadcast information based on the information
received from mobile device 404. If the information received from mobile device 404
is utilized to update the broadcast signal, the updated signal can be broadcast 414
(and 408) and heard by a subsequent mobile device 406 that enters the geographic range
of access point 402. As such, mobile device 406 can benefit from the updated (and
potentially correct) information in the broadcast signal to mitigate the amount of
time to establish a communication, illustrated at 416, with access point 402. Mobile
device 406 can provide a recommendation to access point 402 if the broadcast information
(or a sub-portion of the broadcast information) is incorrect in a manner similar to
that described above. If the broadcast information is correct, mobile device 406 may
provide such information to access point 402, however such notification is not necessary.
[0064] Referring to Figs. 5-6, methodologies relating to updating broadcast information
so that subsequent communication of such broadcast information provides more accurate
information that can be relied upon are illustrated. While, for purposes of simplicity
of explanation, the methodologies are shown and described as a series of acts, it
is to be understood and appreciated that the methodologies are not limited by the
order of acts, as some acts may, in accordance with one or more aspects, occur in
different orders and/or concurrently with other acts from that shown and described
herein. For example, those skilled in the art will understand and appreciate that
a methodology could alternatively be represented as a series of interrelated states
or events, such as in a state diagram. Moreover, not all illustrated acts may be required
to implement a methodology in accordance with one or more aspects.
[0065] Fig. 5 is an illustration of an example methodology 500 that facilitates selectively adjusting
information included in a broadcast signal within a wireless communication environment.
Method 500 starts, at 502, when information including power control information is
broadcast (e.g. periodically, continuously). Such information can be broadcast to
one or a multitude of devices within a geographic range or vicinity wherein such devices
partially or completely rely on such broadcast information. The broadcast signal can
include information relating to an access point receive power target, an access point
transmit power, a power offset, a path loss or combinations thereof and/or other information.
In some situations, access point power target (or other information included in the
signal) is not correct and mobile devices that come within the vicinity of an access
point that rely on this information to communicate with the access point can not obtain
instantaneous communication with access point. For example, if the power target is
too low, the access point might not hear the communication from the mobile device.
If the power target is too high, interference can be caused to other devices in the
vicinity. Access point might request corrected information from the mobile devices
if a portion or subset of the information (power target, power offset or other information)
included in the broadcast signal is determined to be incorrect by a mobile device.
In accordance with some aspects, the broadcast signal includes a request that one
or more mobile devices confirm if the information included in the broadcast signal
is correct or if it is incorrect.
[0066] At 504, corrected information is received in a reply signal from one or more mobile
devices. The corrected information can include one or more modifications to the information
that was sent in the broadcast signal. For example, one or more mobile devices can
determine what information in the broadcast signal should be modified in order for
subsequent mobile devices to receive the correct information in an initial communication
(e.g., signal) from the access point. The corrected information can include offset
information or other information that might mitigate the amount of time devices need
to establish communication with access point. In accordance with some aspects, if
there are no corrections needed to the broadcast signal, a reply signal is not received
at 504. In accordance with other aspects, a reply signal is received, at 504, indicating
that the broadcast signal information is correct.
[0067] The modified information received from the one or more mobile devices can be selectively
applied by access point, at 506, to correct the information included in the broadcast
signal. For example, access point might selectively adjust its broadcast information
if access point determines that the information is reliable. The information might
not be deemed reliable unless a confidence level is reached. The confidence level
can be derived, in part, on the reliability of the mobile device based on historical
information or based on other criteria. Until the information is deemed reliable,
the modification might not be applied to the broadcast signal.
[0068] However, if the information is determined to be unreliable or not corroborated by
other devices, access point might not adjust the broadcast information. In some situations,
access point might request further information from the same mobile device or from
other mobile devices that can hear the broadcast signal. For example, access point
can request corroboration of the at least one modification from a second (or more
mobile devices) before updating the broadcast signal.
[0069] Access point may make modifications to the information received from one or more
mobile devices before applying such modifications to the information included in the
broadcast signal. For example, the measurements (or other information) received from
more than one device might be averaged if the measurements do not match and/or are
similar. Other criteria can also be utilized to selectively modify information (e.g.,
the identification of the mobile device supplying the modification information, the
reliability of the mobile device based on historical information, and so forth). The
method 500 can continue, at 502, when modified (or the same) information is broadcast.
As such, the information included in the broadcast signal can be continuously modified,
as needed, when changes within the communications network occur that render at least
a subset of the broadcast signal information not correct. In accordance with some
aspects, feedback information (e.g., notification whether the broadcast information
is correct or incorrect) can be requested and/or received from at least one mobile
device periodically or continuously to verify that the broadcast information remains
as correct as possible.
[0070] With reference to
Fig. 6, illustrated is a methodology 600 that facilitates automatic correction of broadcast
information through a feedback mechanism. Method 600 starts, at 602 when broadcast
information is received. This information can be received at (or actively sought out)
when a device enters the geographic area of a base station (e.g., is handed off, upon
power-up and so forth). The broadcast information can include various types of information
including, but not limited to, an identification of an access point, an access point
transmit power level, an access point receive power target level, an offset value,
as well as other information that can be utilized by a mobile device to identify and
use access point.
[0071] The information included in the broadcast signal might be correct or there might
be one or more portions of the information in the broadcast signal that are inaccurate.
If the information is correct, the mobile device can quickly establish communication
with access point. The mobile device may send a confirmation to access point indicating
that the information is correct, however, this is not necessary.
[0072] If the information or a subset of the information in the broadcast signal is incorrect,
a determination is made as to which information is incorrect, at 604. Such a determination
can be made based on using the information to establish a communication and, if the
communication is not established within a predetermined interval, modifying the information
(e.g., adjusting a transmit power level) until communication is established. For example,
an access point transmit power and a device receiver power can be compared to determine
the difference between the two powers. The access point transmit power can be known
from information included in the broadcast signal. The difference between the two
powers can be referred to as a power loss or power offset value. Additionally or alternatively,
calculations can be performed to correct the information or other actions can be taken
to determine if any of the information is incorrect and to ascertain necessary corrections.
In accordance with some aspects the broadcast signal can include a request for the
mobile device to verify whether a subset (or all) information included in the broadcast
signal is accurate and/or needs changes.
[0073] At 606, a message including recommended changes can be conveyed (e.g., in a feedback
signal) to the device that sent the broadcast information, such as an access point.
For example, the power offset information can be provided to the access point recommending
that the power offset information be included in a subsequent broadcast signal. The
device that sent the broadcast information can selectively modify the broadcast information
and convey the modified broadcast information until another change is recommended,
which can be selectively applied. As such, if changes are determined to be needed
in the broadcast information, these changes can be made so that devices that receive
the broadcast information at a later time receive corrected or modified information
deemed to be correct. In accordance with some aspects, the access point can be notified
if the information included in the broadcast signal does not need modification (e.g.,
is correct), however such notification is not necessary.
[0074] It will be appreciated that, in accordance with one or more aspects described herein,
inferences can be made regarding dynamically updating broadcast information. As used
herein, the term to "infer" or "inference" refers generally to the process of reasoning
about or inferring states of the system, environment, and/or user from a set of observations
as captured through events and/or data. Inference can be employed to identify a specific
context or action, or can generate a probability distribution over states, for example.
The inference can be probabilistic-that is, the computation of a probability distribution
over states of interest based on a consideration of data and events. Inference can
also refer to techniques employed for composing higher-level events from a set of
events and/or data. Such inference results in the construction of new events or actions
from a set of observed events and/or stored event data, whether or not the events
are correlated in close temporal proximity, and whether the events and data come from
one or several event and data sources.
[0075] According to an example, one or more methods presented above can include making inferences
pertaining to selectively making changes to information included in a broadcast signal.
In accordance with another example, an inference can be made related to a number of
verifications that should be received based on a type of information that is recommended
to be changed. According to a further example, an inference can be made pertaining
to a likelihood of a recommended change being accurate based upon an identification
of a device that provided the recommendation. It will be appreciated that the foregoing
examples are illustrative in nature and are not intended to limit the number of inferences
that can be made or the manner in which such inferences are made in conjunction with
the various aspects described herein.
[0076] Fig. 7 depicts an example communication system 700 implemented in accordance with
various aspects including multiple cells: cell I 702, cell M 704. Note that neighboring
cells 702, 704 overlap slightly, as indicated by cell boundary region 768, thereby
creating potential for signal interference between signals transmitted by base stations
in neighboring cells. Each cell 702, 704 of system 700 includes three sectors. Cells
which have not be subdivided into multiple sectors (N=1), cells with two sectors (N=2)
and cells with more than 3 sectors (N>3) are also possible in accordance with various
aspects. Cell 702 includes a first sector, sector I 710, a second sector, sector II
712, and a third sector, sector III 714. Each sector 710, 712, 714 has two sector
boundary regions; each boundary region is shared between two adjacent sectors.
[0077] Sector boundary regions provide potential for signal interference between signals
transmitted by base stations in neighboring sectors. Line 716 represents a sector
boundary region between sector I 710 and sector II 712; line 718 represents a sector
boundary region between sector II 712 and sector III 714; line 720 represents a sector
boundary region between sector III 714 and sector 1 710. Similarly, cell M 704 includes
a first sector, sector I 722, a second sector, sector II 724, and a third sector,
sector III 726. Line 728 represents a sector boundary region between sector I 722
and sector II 724; line 730 represents a sector boundary region between sector II
724 and sector III 726; line 732 represents a boundary region between sector III 726
and sector 1722. Cell I 702 includes a base station (BS), base station I 706, and
a plurality of end nodes (ENs) (e.g., wireless terminals) in each sector 710, 712,
714. Sector I 710 includes EN(1) 736 and EN(X) 738 coupled to BS 706 by wireless links
740, 742, respectively; sector II 712 includes EN(1') 744 and EN(X') 746 coupled to
BS 706 by wireless links 748, 750, respectively; sector III 714 includes EN(1") 752
and EN(X") 754 coupled to BS 706 by wireless links 756, 758, respectively. Similarly,
cell M 704 includes base station M 708, and a plurality of end nodes (ENs) in each
sector 722, 724, 726. Sector I 722 includes EN(1) 736' and EN(X) 738' coupled to BS
M 708 by wireless links 740', 742', respectively; sector II 724 includes EN(1') 744'
and EN(X') 746' coupled to BS M 708 through wireless links 748', 750', respectively;
sector 3 726 includes EN(1") 752' and EN(X") 754' coupled to BS 708 by wireless links
756', 758', respectively.
[0078] System 700 also includes a network node 760 which is coupled to BS I 706 and BS M
708 by network links 762, 764, respectively. Network node 760 is also coupled to other
network nodes, (e.g., other base stations, AAA server nodes, intermediate nodes, routers,
and so forth) and the Internet through network link 766. Network links 762, 764, 766
may be, example, fiber optic cables. Each end node, such as EN(1) 736, may be a wireless
terminal including a transmitter as well as a receiver. The wireless terminals, (e.g.,
EN(1) 736) may move through system 700 and may communicate through wireless links
with the base station in the cell in which the EN is currently located. The wireless
terminals, (WTs) (e.g., EN(1) 736), may communicate with peer nodes, (e.g., other
WTs in system 700 or outside system 700) through a base station, such as, BS 706,
and/or network node 760. WTs, such as EN(1) 736 may be mobile communications devices
such as cell phones, personal data assistants with wireless modems,
etc.
[0079] Respective base stations perform tone subset allocation using a different method
for the strip-symbol periods, from the method employed for allocating tones and determining
tone hopping in the rest symbol periods (e.g., non strip-symbol periods). The wireless
terminals use the tone subset allocation method along with information received from
the base station (e.g., base station slope ID, sector ID information) to determine
tones that they can employ to receive data and information at specific strip-symbol
periods. The tone subset allocation sequence is constructed, in accordance with various
aspects to spread inter-sector and inter-cell interference across respective tones.
[0080] Fig. 8 illustrates an example base station 800 in accordance with various aspects.
Base station 800 implements tone subset allocation sequences, with different tone
subset allocation sequences generated for respective different sector types of the
cell. Base station 800 may be used as any one of base stations 706, 708 of the system
700 of Fig. 7. The base station 800 includes a receiver 802, a transmitter 804, a
processor 806 (e.g., CPU), an input/output interface 808 and memory 810 coupled together
by a bus 809 over which various elements 802, 804, 806, 808, and 810 may interchange
data and information.
[0081] Sectorized antenna 803 coupled to receiver 802 is used for receiving data and other
signals, e.g., channel reports, from wireless terminals transmissions from each sector
within the base station's cell. Sectorized antenna 805 coupled to transmitter 804
is used for transmitting data and other signals (e.g., control signals, pilot signal,
beacon signals, and so forth) to wireless terminals 900 (see Fig. 9) within each sector
of the base station's cell. In various aspects, base station 800 may employ multiple
receivers 802 and multiple transmitters 804, for example, an individual receiver 802
for each sector and an individual transmitter 804 for each sector. Processor 806 may
be, for example, a general purpose central processing unit (CPU). Processor 806 controls
operation of base station 800 under direction of one or more routines 818 stored in
memory 810 and implements the methods. Input/Output (I/O) interface 808 provides a
connection to other network nodes, coupling the BS 800 to other base stations, access
routers, AAA server nodes,
etc., other networks, and the Internet. Memory 810 includes routines 818 and data/information
820.
[0082] Data/information 820 includes data 836, tone subset allocation sequence information
838 including downlink strip-symbol time information 840 and downlink tone information
842, and wireless terminal (WT) data/info 844 including a plurality of sets of WT
information: WT 1 info 846 and WT N info 860. Each set of WT info (e.g., WT 1 info
846) includes data 848, terminal ID 850, sector ID 852, uplink channel information
854, downlink channel information 856, and mode information 858.
[0083] Routines 818 include communications routines 822, base station control routines 824,
and data update routines 862. Base station control routines 824 includes a scheduler
module 826 and signaling routines 828 including a tone subset allocation routine 830
for strip-symbol periods, other downlink tone allocation hopping routine 832 for the
rest of symbol periods (e.g., non strip-symbol periods), and a beacon routine 834.
Data update routines 862 can further include feedback evaluation routines (not shown)
and/or device characteristic evaluation routines (not shown).
[0084] Data 836 includes data to be transmitted that will be sent to encoder 814 of transmitter
804 for encoding prior to transmission to WTs, and received data from WTs that has
been processed through decoder 812 of receiver 802 following reception. Downlink strip-symbol
time information 840 includes the frame synchronization structure information, such
as the superslot, beaconslot, and ultraslot structure information and information
specifying whether a given symbol period is a strip-symbol period, and if so, the
index of the strip-symbol period and whether the strip-symbol is a resetting point
to truncate the tone subset allocation sequence used by the base station. Downlink
tone information 842 includes information including a carrier frequency assigned to
the base station 800, the number and frequency of tones, and the set of tone subsets
to be allocated to the strip-symbol periods, and other cell and sector specific values
such as slope, slope index and sector type.
[0085] Data 848 may include data that WT1 900 has received from a peer node, data that WT
1 900 desires to be transmitted to a peer node, and downlink channel quality report
feedback information. Terminal ID 850 is a base station 800 assigned ID that identifies
WT 1900. Sector ID 852 includes information identifying the sector in which WT1 900
is operating. Sector ID 852 can be used, for example, to determine the sector type.
Uplink channel information 854 includes information identifying channel segments that
have been allocated by scheduler 826 for WT1 900 to use (e.g., uplink traffic channel
segments for data, dedicated uplink control channels for requests, power control,
timing control, an so forth).
[0086] Each uplink channel assigned to WT1 900 includes one or more logical tones, each
logical tone following an uplink hopping sequence. Downlink channel information 856
includes information identifying channel segments that have been allocated by scheduler
826 to carry data and/or information to WT1 900 (e.g., downlink traffic channel segments
for user data). Each downlink channel assigned to WT1 900 includes one or more logical
tones, each following a downlink hopping sequence. Mode information 858 includes information
identifying the state of operation of WT1 900 (
e.g.,. sleep, hold, on).
[0087] Communications routines 822 control the base station 800 to perform various communications
operations and implement various communications protocols. Base station control routines
824 are used to control the base station 800 to perform basic base station functional
tasks (e.g., signal generation and reception, scheduling) and to implement the steps
of the method of some aspects including transmitting signals to wireless terminals
using the tone subset allocation sequences during the strip-symbol periods.
[0088] Signaling routine 828 controls the operation of receiver 802 with its decoder 812
and transmitter 804 with its encoder 814. The signaling routine 828 is responsible
for controlling the generation of transmitted data 836 and control information. Tone
subset allocation routine 830 constructs the tone subset to be used in a strip-symbol
period using the method of the aspect and using data/information 820 including downlink
strip-symbol time info 840 and sector ID 852. The downlink tone subset allocation
sequences will be different for each sector type in a cell and different for adjacent
cells.
[0089] The WTs 900 receive the signals in the strip-symbol periods in accordance with the
downlink tone subset allocation sequences; the base station 800 uses the same downlink
tone subset allocation sequences in order to generate the transmitted signals. Other
downlink tone allocation hopping routine 832 constructs downlink tone hopping sequences,
using information including downlink tone information 842, and downlink channel information
856, for the symbol periods other than the strip-symbol periods. The downlink data
tone hopping sequences are synchronized across the sectors of a cell. Beacon routine
834 controls the transmission of a beacon signal (e.g., a signal of relatively high
power signal concentrated on one or a few tones), which may be used for synchronization
purposes (e.g., to synchronize the frame timing structure of the downlink signal)
and therefore the tone subset allocation sequence with respect to an ultra-slot boundary.
[0090] Data update routines 862 can further include feedback evaluation routines (not shown)
and/or device characteristic evaluation routines (not shown). Feedback can be evaluated
to determine if data included in a transmitted signal should be updated, deleted,
added and so forth. The feedback can be from one or more devices and can relate to
all or a sub-portion of data transmitted by base station 800. Additionally and/or
alternatively, characteristics associated with a device that provided the feedback
can be evaluated to determine if the data should be modified. Moreover, data update
routines 862 can control data modification based on a confidence level associated
with the modified data and/or the device that supplied the modification. In accordance
with some aspects, the data update routines 862 can be based on an aggregate of feedback
received and/or based on other criteria.
[0091] Fig. 9 illustrates an example wireless terminal (e.g., end node, mobile device, ...) 900
that can be used as any one of the wireless terminals (e.g., end nodes, mobile devices,
...), e.g., EN(1) 736, of the system 700 shown in Fig. 7. Wireless terminal 900 implements
the tone subset allocation sequences. Wireless terminal 900 includes a receiver 902
including a decoder 912, a transmitter 904 including an encoder 914, a processor 906,
and memory 908 which are coupled together by a bus 910 over which the various elements
902, 904, 906, 908 can interchange data and information. An antenna 903 used for receiving
signals from a base station 800 (and/or a disparate wireless terminal) is coupled
to receiver 902. An antenna 905 used for transmitting signals, such as to base station
800 (and/or a disparate wireless terminal) is coupled to transmitter 904.
[0092] The processor 906 (e.g., a CPU) controls operation of wireless terminal 900 and implements
methods by executing routines 920 and using data/information 922 in memory 908. Data/information
922 includes user data 934, user information 936, and tone subset allocation sequence
information 950. User data 934 may include data, intended for a peer node, which will
be routed to encoder 914 for encoding prior to transmission by transmitter 904 to
base station 800, and data received from the base station 800 which has been processed
by the decoder 912 in receiver 902. User information 936 includes uplink channel information
938, downlink channel information 940, terminal ID information 942, base station ID
information 944, sector ID information 946, and mode information 948.
[0093] Uplink channel information 938 includes information identifying uplink channels segments
that have been assigned by base station 800 for wireless terminal 900 to use when
transmitting to the base station 800. Uplink channels may include uplink traffic channels,
dedicated uplink control channels (e.g., request channels, power control channels
and timing control channels). Each uplink channel includes one or more logic tones,
each logical tone following an uplink tone hopping sequence. The uplink hopping sequences
are different between each sector type of a cell and between adjacent cells. Downlink
channel information 940 includes information identifying downlink channel segments
that have been assigned by base station 800 to WT 900 for use when BS 800 is transmitting
data/information to WT 900. Downlink channels may include downlink traffic channels
and assignment channels, each downlink channel including one or more logical tone,
each logical tone following a downlink hopping sequence, which is synchronized between
each sector of the cell.
[0094] User info 936 also includes terminal ID information 942, which is a base station
800 assigned identification, base station ID information 944 that identifies the specific
base station 800 that WT has established communications with, and sector ID info 946,
which identifies the specific sector of the cell where WT 900 is presently located.
Base station ID 944 provides a cell slope value and sector ID info 946 provides a
sector index type; the cell slope value and sector index type may be used to derive
tone hopping sequences. Mode information 948 also included in user info 936 identifies
whether the WT 900 is in sleep mode, hold mode, or on mode.
[0095] Tone subset allocation sequence information 950 includes downlink strip-symbol time
information 952 and downlink tone information 954. Downlink strip-symbol time information
952 include the frame synchronization structure information, such as the superslot,
beaconslot, and ultraslot structure information and information specifying whether
a given symbol period is a strip-symbol period, and if so, the index of the strip-symbol
period and whether the strip-symbol is a resetting point to truncate the tone subset
allocation sequence used by the base station. Downlink tone info 954 includes information
including a carrier frequency assigned to the base station 800, the number and frequency
of tones, and the set of tone subsets to be allocated to the strip-symbol periods,
and other cell and sector specific values such as slope, slope index and sector type.
[0096] Routines 920 include communications routines 924, wireless terminal control routines
926, information correction routines 928 and notification routines 930. Communications
routines 924 control the various communications protocols used by WT 900. By way of
example, communications routines 924 may enable receiving a broadcast signal (e.g.,
from base station 800). Wireless terminal control routines 926 control basic wireless
terminal 900 functionality including the control of the receiver 902 and transmitter
904.
[0097] Information correction routines 928 can control selective correction of information
included in a signal received from an access point. The selective correction can relate
to information utilized by wireless terminal 900 to identify and establish communication
with access point. For example, the correction can relate to a power offset or other
information that should be included in the signal or that should be modified. Notification
routines 930 can control notification of the corrections and/or verification of the
correctness of information included in the signal.
[0098] With reference to
Fig. 10, illustrated is an example system 1000 that enables selective modification of broadcast
information within a wireless communications environment. For example, system 1000
may reside at least partially within a mobile device. It is to be appreciated that
system 1000 is represented as including functional blocks, which may be functional
blocks that represent functions implemented by a processor, software, or combination
thereof (e.g., firmware). System 1000 includes a logical grouping 1002 of electrical
components that can act individually and/or in conjunction.
[0099] Logical grouping 1002 may include an electrical component for identifying incorrect
information received in a signal 1104. The signal can be received from an access point
and can include a variety of information including but not limited to an access point
power target, an access point transmit power, a power offset, and so forth. Also,
including in the signal can be a request to verify at least a portion of the information
included in the signal.
[0100] Further, logical grouping 1002 can comprise an electrical component for determining
a recommended modification 1106. The recommended modification can be a modification
relating to information in the signal that should be changed, added, deleted,
etc. For example, a logical module can determine a power offset value. The power offset
value can be based in part on information included in the signal, such as an access
point transmit power. The access point transmit power can be compared to a receive
power and the difference between the two powers determined, which can be referred
to as the power offset value.
[0101] Logical grouping 1002 can include an electrical component for sending the recommended
modification in a feedback signal 1108. The recommended modification can be a power
offset value that should be included (or updated) in the signal. By way of illustration,
the feedback signal can be sent to access point, wherein access point can use the
information to selectively modify information in the signal. In accordance with some
aspects, a result of the verification (if one was requested) can be conveyed to the
access point. A next signal can be received from an access point and evaluated. The
result of whether the next signal is correct or incorrect can be sent in a feedback
notification to the access point.
[0102] Additionally, system 1000 may include a memory 1010 that retains instructions for
executing functions associated with electrical components 1004, 1006, and 1008. While
shown as being external to memory 1010, it is to be understood that one or more of
electrical components 1004, 1006, and 1008 may exist within memory 1010.
[0103] With reference to
Fig. 11, illustrated is a system 1100 that can mitigate a length of an initial access phase
in a wireless environment. For example, system 1100 may reside at least partially
within a base station. It is to be appreciated that system 1100 is represented as
including functional blocks, which may be functional blocks that represent functions
implemented by a processor, software, or combination thereof (e.g., firmware). System
1100 includes a logical grouping 1102 of electrical components that can act independently
and/or in conjunction. For instance, logical grouping 1102 may include an electrical
component for identifying information to include in a broadcast signal 1104. The broadcast
information can be sent to multiple devices and can include a variety of information
relating to system 1100 and can include information that various devices can receive
and rely upon to identify and gain access (e.g., initial access phase) to system 1100.
Broadcast information can also include requests for the one or more of the devices
to respond and/or verify the accuracy of the information included in the broadcast
signal.
[0104] Further, logical grouping 1102 can comprise an electrical component for receiving
reply signals from one or more of the devices 1106. The reply signal can be in response
to the broadcast signal. For example, one or more of the various devices can automatically
provide updated information and/or a recommendation to modify one or more portions
of information in the broadcast signal if the device determines that the information
is incorrect. In accordance with some aspects, if the information is correct, one
or more devices can reply indicating that the information is accurate. Additionally
and/or alternatively, one or more devices might only provide a recommendation or other
feedback if there is a request for such information included in the broadcast signal.
[0105] Moreover, logical grouping 1102 can include an electrical component for changing
at least a subset of the information included in the broadcast signal 1108. The change
can be based on the one or more reply signals or can be based on other criteria. By
way of illustration, changing at least a subset of the information can be optimized
by considering various characteristics of one or more received reply signals and/or
the characteristics of the devices supplying the recommendations. For example, if
more than one reply signal is received an average or aggregate of the signals can
be utilized to change the information. A confidence level of accuracy of the information
(e.g., reply signal) supplied by one or more devices can be analyzed to determine
if information within the broadcast signal should be changed. The information changed
can relate to power or other information wherein corrected information can mitigate
the amount of time that a subsequent device takes to identify and gain access to system
1100. A request can be sent in a subsequent broadcast signal for devices within the
vicinity to verify the accuracy of the modified information.
[0106] It is to be understood that the aspects described herein may be implemented in hardware,
software, firmware, middleware, microcode, or any combination thereof. For a hardware
implementation, the processing units may be implemented within one or more application
specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal
processing devices (DSPDs), programmable logic devices (PLDs), field programmable
gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors,
other electronic units designed to perform the functions described herein, or a combination
thereof.
[0107] When the aspects are implemented in software, firmware, middleware or microcode,
program code or code segments, they may be stored in a machine-readable medium, such
as a storage component. A code segment may represent a procedure, a function, a subprogram,
a program, a routine, a subroutine, a module, a software package, a class, or any
combination of instructions, data structures, or program statements. A code segment
may be coupled to another code segment or a hardware circuit by passing and/or receiving
information, data, arguments, parameters, or memory contents. Information, arguments,
parameters, data,
etc. may be passed, forwarded, or transmitted using any suitable means including memory
sharing, message passing, token passing, network transmission,
etc.
[0108] For a software implementation, the techniques described herein may be implemented
with modules (e.g., procedures, functions, and so on) that perform the functions described
herein. The software codes may be stored in memory units and executed by processors.
The memory unit may be implemented within the processor or external to the processor,
in which case it can be communicatively coupled to the processor through various means
as is known in the art.
[0109] What has been described above includes examples of one or more aspects. It is, of
course, not possible to describe every conceivable combination of components or methodologies
for purposes of describing the aforementioned aspects, but one of ordinary skill in
the art may recognize that many further combinations and permutations of various aspects
are possible. Accordingly, the described aspects are intended to embrace all such
alterations, modifications and variations that fall within the spirit and scope of
the appended claims. Furthermore, to the extent that the term "includes" is used in
either the detailed description or the claims, such term is intended to be inclusive
in a manner similar to the term "comprising" as "comprising" is interpreted when employed
as a transitional word in a claim. Furthermore, the term "or" as used in either the
detailed description of the claims is meant to be a "non-exclusive or".
1. A method that facilitates selective adjustment of power control information sent in
a broadcast signal, comprising:
receiving a broadcast signal from an access point, the broadcast signal includes power
control information;
ascertaining if a correction is recommended for the broadcast power control information;
and
conveying the recommended correction to the access point.
2. The method of claim 1, conveying the recommended correction to the access point is
provided as a feedback signal.
3. The method of claim 1, ascertaining if a correction is recommended further comprises
comparing a difference between an access point transmit power and a device receive
power and assigning the difference as a power loss.
4. The method of claim 3, further comprising sending the power loss information to the
access point as a recommendation to include the power loss information in a subsequent
broadcast signal.
5. The method of claim 1, further comprising notifying the access point if the power
control information received in the broadcast signal does not need modification.
6. The method of claim 1, further comprising responding to a request included in the
broadcast signal wherein the request includes verifying whether at least a portion
of the power control information included in the broadcast signal is correct.
7. The method of claim 1, wherein the recommended correction is a power offset value.
8. A wireless communications apparatus, comprising:
a memory that retains instructions related to evaluating power control information
included in a broadcast signal, determining if there is at least one error in the
information and notifying an access point of the at least one error in a feedback
signal; and
a processor, coupled to the memory, configured to execute the instructions retained
in the memory.
9. The wireless communications apparatus of claim 8, wherein the memory further retains
instructions for determining a power offset value by comparing an access point transmit
power with a device receive power and setting a transmit power to a sum of the offset
value and an access point receive power target.
10. The wireless communications apparatus of claim 8, wherein the memory further retains
instructions for notifying the access point if the power control information contained
in the broadcast signal is correct.
11. The wireless communications apparatus of claim 8, wherein the memory further retains
instructions for recommending that the access point correct the error in a next broadcast
signal.
12. The wireless communications apparatus of claim 8, wherein the error is a power offset
value.
13. The wireless communications apparatus of claim 8, wherein the memory further retains
instructions for reviewing a next broadcast signal and providing information relating
to an accuracy of the next broadcast signal.
14. A wireless communications apparatus that enables selective modification of broadcast
information within a wireless communications environment, comprising:
means for identifying incorrect information included in a signal from an access point;
means for determining a recommended modification for the identified incorrect information;
and
means for sending the recommended modification in a feedback signal to the access
point.
15. The wireless communications apparatus of claim 14, further comprising:
means for evaluating a next signal from the access point; and
means for notifying the access point if the next signal is correct or includes incorrect
information.
16. The wireless communications apparatus of claim 14, further comprising:
means for determining a power offset value based in part on information included in
the signal; and
means for communicating the power offset value to the access point.
17. The wireless communications apparatus of claim 14, further comprising:
means for receiving a request from the access point to verify at least a portion of
the information included in the signal; and
means for providing a result of the verification to the access point.
18. A machine-readable medium having stored thereon machine-executable instructions for:
evaluating a correctness of a signal from an access point;
determining at least one recommended change to the signal; and
sending the at least one recommended change to the access point in a feedback signal.
19. The machine-readable medium of claim 18, the machine-executable instructions further
comprise:
receiving a receive power target for the access point;
measuring a power at which the signal was received;
determining a difference between the access point receive power target and the power
at which the signal was received; and
identifying the determined difference point as a power offset value.
20. The machine-readable medium of claim 19, the machine-executable instructions further
comprise recommending that the power offset value be included in a next signal from
the access point.
21. The machine-readable medium of claim 18, the machine-executable instructions further
comprise:
verifying the information included in the signal is correct; and
sending a notification to the access point indicating that the information is correct.
22. In a wireless communication system, an apparatus comprising:
a processor configured to:
identify inaccurate information included in a signal from an access point;
determine a change that will correct the inaccurate information, the determined change
can be based at least in part on information included in the signal; and
provide a feedback signal to the access point, the feedback signal includes the determined
change.
23. A method that facilitates selective adjustment of information included in a broadcast
signal, comprising:
broadcasting a signal that includes power control information, the signal is broadcast
to at least one device within a geographic area;
receiving a reply signal from the at least one device, the reply signal includes at
least one modification to the power control information included in the broadcast
signal; and
selectively applying the at least one modification to the power control information
included in the broadcast signal.
24. The method of claim 23, wherein the reply signal includes power offset information.
25. The method of claim 23, broadcasting a signal that includes power control information
further comprises requesting at least one modification to the information if at least
a portion of the information is incorrect.
26. The method of claim 23, further comprising receiving feedback from the at least one
device periodically.
27. The method of claim 23, further comprising receiving feedback from the at least one
device continuously.
28. The method of claim 23, wherein the broadcast information relates to at least one
of an access point transmit power, an access point receive power target, a path loss,
or a power offset, or combinations thereof.
29. The method of claim 23, further comprising broadcasting a modified signal that includes
the at least one modification.
30. The method of claim 23, broadcasting a signal that includes information further comprises
requesting a confirmation to determine if the information included in the broadcast
signal is correct.
31. The method of claim 23, selectively applying the at least one modification to the
information included in the broadcast signal further comprises requesting corroboration
of the at least one modification from at least a second device.
32. The method of claim 23, further comprising:
receiving at least a second reply signal from a second device, the at least a second
reply signal includes a modification similar to the at least one modification; and
applying an average of the modifications to the information included in the broadcast
signal.
33. The method of claim 23, selectively applying the at least one modification to the
information included in the broadcast signal further comprises waiting until a confidence
level is reached before applying the at least one modification.
34. The method of claim 33, wherein the confidence level is derived in part on a reliability
of the device based on historical information.
35. A wireless communications apparatus, comprising:
a memory that retains instructions related to determining information to include in
a broadcast signal; receiving a device recommendation to update information included
in the broadcast signal, and selectively modifying the broadcast signal information
based in part on the received device recommendation; and
a processor, coupled to the memory, configured to execute the instructions retained
in the memory.
36. The wireless communications apparatus of claim 35, wherein the information included
in the broadcast signal relates to at least one of an access point transmit power,
an access point receive power target, a path loss, or a power offset, or combinations
thereof.
37. The wireless communications apparatus of claim 35, wherein the memory further retains
instructions for determining a confidence level associated with the device that provided
the recommendation.
38. The wireless communications apparatus of claim 35, wherein the memory further retains
instructions for requesting corroboration of the provided recommendation from at least
a second device.
39. The wireless communications apparatus of claim 35, wherein the memory further retains
instructions for requesting confirmation of the information included in the broadcast
signal.
40. The wireless communications apparatus of claim 35, wherein the memory further retains
instructions for averaging values received from a plurality of devices before selectively
modifying the information in the broadcast signal.
41. The wireless communications apparatus of claim 35, wherein the memory further retains
instructions for receiving feedback after modifying the broadcast signal from the
device that provided the recommendation to verify appropriate modifications were made.
42. A wireless communications apparatus that mitigates a length of an initial access phase
in a wireless environment, comprising:
means for identifying information to include in a broadcast signal sent to a plurality
of devices;
means for receiving at least one reply signal from at least one of the plurality of
devices in response to the broadcast signal; and
means for changing at least a subset of the information included in the broadcast
signal based in part on the at least one reply signal.
43. The wireless communications apparatus of claim 42, further comprising means for requesting
that the at least one of the plurality of devices verify an accuracy of the information
included in the broadcast signal.
44. The wireless communications apparatus of claim 42, further comprising means for analyzing
characteristics associated with the at least one of the plurality of devices that
that provided the reply signal.
45. The wireless communications apparatus of claim 42, further comprising means for analyzing
a confidence level associated with the at least one of the plurality of devices before
the broadcast signal information is changed.
46. The wireless communications apparatus of claim 42, further comprising means for aggregating
a plurality of reply signals.
47. The wireless communications apparatus of claim 42, further comprising a means for
requesting verification of an accuracy of a modified broadcast signal.
48. A machine-readable medium having stored thereon machine-executable instructions for:
transmitting a signal that at least one device relies upon to gain access to a communications
network;
evaluating feedback from the at least one device to identify incorrect information
included in the transmitted signal; and
adapting the transmitted signal based upon the feedback evaluation.
49. The machine-readable medium of claim 48, the machine-executable instructions further
comprise determining a confidence level associated with the feedback or the at least
one device.
50. The machine-readable medium of claim 48, the machine-executable instructions further
comprise identifying at least one of an access point transmit power, an access point
receive power target, a path loss, or a power offset, or combinations thereof, to
include in the broadcast signal.
51. The machine-readable medium of claim 48, the machine-executable instructions further
comprise aggregating feedback from at least a second device with the feedback from
the at least one device before adapting the transmitted signal.
52. The machine-readable medium of claim 48, the machine-executable instructions further
comprise requesting verification of the feedback from at least a second device.
53. The machine-readable medium of claim 48, the machine-executable instructions further
comprise transmitting the adapted signal to a plurality of devices.
54. In a wireless communication system, an apparatus comprising:
a processor configured to:
identify information to include in a broadcast signal, the broadcast signal is sent
to a plurality of devices;
evaluate one or more modifications to the information in the broadcast signal, the
one or more modifications are received from a subset of the plurality of devices;
and
modify the information included in a subsequent broadcast signal based on the one
or more modifications received.